Camera Properties Mode State is a checkbox that determines whether or not to use an external trigger. The default is off. Trigger Source and Trigger Activation have no effect unless the trigger is enabled. Trigger Source is for cameras that support multiple trigger lines. Specify which line will be used to cause an image to be taken. The Trigger Activation field specifies which part of the trigger signal to react to. For line scan cameras, you must specify what signals trigger the start of a frame and the start of a line. Refer to the following figure: ACEUser's Guide, 3.6.x, 18316-000 Rev A Page 341